In the above-described technical field, patent literature 1 discloses a technique of causing a collation server to collate browsing moving image data uploaded from a client to a site with moving image data already registered by a registrant, as shown in FIG. 1, thereby determining whether the moving image data can be uploaded. Also mentioned is speeding up the processing by causing the collation server to do the collation for a still image group extracted arbitrarily or at random (see paragraphs [0045] and [0046]). It is also suggested that when browsing moving image data is uploaded directly from a client to a site, a reference server acquires the browsing moving image data from the site and collates it (see paragraph [0031]).